Carriage rinofaringeo: distribuzione dei sierotipi diStreptococcus pneumoniaee di altri patogeni respiratori

Aim: Bacterial colonization is thought to be a prerequisite for an individual to become infected, but bacterial colonisation does not normally result in infection.Streptococcus pneumonieinfection is a major cause of childhood morbidity and mortality worldwide. The aim of this study is to understand the epidemiology of nasopharyngeal carriage ofStreptococcus pneumoniaeand other respiratory pathogens, in vaccinated children for implementing appropriate vaccination strategies.Methods: 217 nasopharyngeal swabs were collected in a cohort population forvaccination, aged 3 to 13 years in northern Sardinia. Pneumococcal and other respiratory pathogens nasopharyngeal carriage prevalence and serogroups distribution were determined using validated molecular and cultural assays.Results: Carriage rates was 22%, overall. TheS. pneumoniaecarriage prevalence was 60%(95% CI, 0,34-0,73),23%(95% CI, 0,13-0,27)and 16%(95% CI, 0,05-0,19)in nursery, in primary school and secondary school, respectively. Overall the most frequentS. pneumoniaserotypes were 18(38%), 4(11%), 19F(4%), 3(17%), 5(15%) and 19A (4%). The onlyN. meningitidisserogroup in nursery and secondary school was B.Conclusion: TheS. pneumoniaecarriage and other common respiratory bacteria prevalence were higher in nursery than in primary and secondary school. This study suggests thatS. pneumoniaeis present in the nasopharynx of the majority of children 3-5 years even if vaccinated. OverallN. meningitidisserogroup B was the most prevalent serogroup detected. The vaccine (Men C) selective pressure could be cause of this epidemiological picture. The study of the pneumococcal and other common respiratory bacteria survey, through analysis of prevalence of different serotypes is important to understand impact assessment of vaccine introduced in regional prevention plans.